This research will produce national-level estimates of levels and correlates of illegal drug use by pregnant women and recent fathers, comparing the periods 1979-84 and 1986-88 (for marijuana use), 1983-84 and 1986-88 (for cocaine use), and 1983-84 (for amphetamines and other drugs). These will include: 1) Levels and correlates of marijuana and cocaine use and changes between the two periods, comparing pregnant women with nonpregnant women in the same birth cohorts. 2) Associations among substance use (illegal drugs, alcohol, and tobacco) during pregnancy and poor health care before and after pregnancy. 3) Levels and correlates of drug use by fathers of infants and small children, and changes between the earlier periods and 1986-88. The data come from the National Longitudinal Survey of Labor Market Experience - Youth Cohort, a probability sample of 5,827 women and 5,579 men aged 14-21 in 1979 (and 23-30 in 1988). The sample was weighted to overrepresent blacks, Hispanics, and low-income whites. Self-report data on drug use from the 1984 and 1988 annual rounds will be matched to fertility histories. Independent variables will include characteristics of the respondent's household of origin; respondent's race/ethnicity, marital status, education and work experience, household income, region of the country, metropolitan residence, and psychological scales; and behavioral variables, including drug, alcohol, and tobacco use before and during pregnancy, adequacy of health care, and degree of involvement in parenting (men respondents). These independent variables were measured prior to the first pregnancy for most respondents. Methods will include multivariate logistic regressions. The analyses will also include study of item nonresponse and estimation of the direction of biases introduced by underreporting of drug use and abortions.